BB2-7030 User Guide – Rev. 1.0
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field processing takes place if the bit field is set to zero. Bit fields apply to 16-bit integer or
unsigned integer server registers only.
The name is optional and is used for display purposes only.
Delete will remove the rule number shown in the "Showing" box. Insert will insert a new rule
before the rule number shown, and is used for placing rules between existing rules. It is not
necessary to use Insert to add rules to the bottom of the list or to define any rule presently having
"none" for register format.
Selecting "none" as the register format effectively deletes the rule even though it will still appear
in the list until deleted. Unused rules at the end of the list will always show "none" as the format.
If you wish to prevent these from being displayed, reduce the number of rules enabled.
Enter the number of Modbus registers that should be available in your customized register
mapping and check "User Map Enabled" to begin using a customized map. Check "Map is
Exclusive" if access to registers outside of this map should be prohibited. If exclusive is not
selected, all local registers not overlapped by the custom map will also be accessible to the
remote client.
By default, double registers in Control Solutions products are "big endian" meaning the most
significant bytes are in the first register and least significant bytes are in the second register. If
remote clients accessing this server at this IP address expect "little endian", check the swap box.
Modbus protocol by definition is "big endian" within each register, but the "endian" order of the
registers for 32-bit values is less standardized.
Normally an attempt to read an undefined register will return an exception (error) code. To
enable reading of large data packets without nuisance errors, you have the option of zero filling
null registers. This means that reading an undefined register in between valid defined registers
will simply return zero data rather than an error.
Check "Use Modicon mapping" to map 0X, 1X, 3X and 4X registers anywhere in i.CanDoIt
register space. When you use Modicon mapping, the Mapped Register number should be in the
following ranges:
Mapped Register # Read (Write) as
Function codes expected
0-9999
Coil
1, 5, 15
10001-19999 Discrete
Input
2
30001-39999 Input
Register
4
40001-49999
Holding Register 3, 6, 16
Any of the Modicon register types may be mapped to any local register, except that coils and
discrete inputs cannot map to floating point registers. When a local register is read as coil or
discrete input, any nonzero value in the local register will return a set bit, and zero in the local
register will return a clear bit. Local registers written as coils will be set to 0 or 1.
